sfc: Rename register I/O header and functions used by both Falcon and Siena

While we're at it, use type suffixes of 'd', 'q' and 'o', consistent
with register type names.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 256 insertions, 0 deletions

diff --git a/drivers/net/sfc/io.h b/drivers/net/sfc/io.h
new file mode 100644
index 0000000..b89177c
--- /dev/null
+++ b/drivers/net/sfc/io.h
@@ -0,0 +1,256 @@
+/****************************************************************************
+ * Driver for Solarflare Solarstorm network controllers and boards
+ * Copyright 2005-2006 Fen Systems Ltd.
+ * Copyright 2006-2009 Solarflare Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+#ifndef EFX_IO_H
+#define EFX_IO_H
+
+#include <linux/io.h>
+#include <linux/spinlock.h>
+
+/**************************************************************************
+ *
+ * NIC register I/O
+ *
+ **************************************************************************
+ *
+ * Notes on locking strategy:
+ *
+ * Most NIC registers require 16-byte (or 8-byte, for SRAM) atomic writes
+ * which necessitates locking.
+ * Under normal operation few writes to NIC registers are made and these
+ * registers (EVQ_RPTR_REG, RX_DESC_UPD_REG and TX_DESC_UPD_REG) are special
+ * cased to allow 4-byte (hence lockless) accesses.
+ *
+ * It *is* safe to write to these 4-byte registers in the middle of an
+ * access to an 8-byte or 16-byte register.  We therefore use a
+ * spinlock to protect accesses to the larger registers, but no locks
+ * for the 4-byte registers.
+ *
+ * A write barrier is needed to ensure that DW3 is written after DW0/1/2
+ * due to the way the 16byte registers are "collected" in the BIU.
+ *
+ * We also lock when carrying out reads, to ensure consistency of the
+ * data (made possible since the BIU reads all 128 bits into a cache).
+ * Reads are very rare, so this isn't a significant performance
+ * impact.  (Most data transferred from NIC to host is DMAed directly
+ * into host memory).
+ *
+ * I/O BAR access uses locks for both reads and writes (but is only provided
+ * for testing purposes).
+ */
+
+#if BITS_PER_LONG == 64
+#define EFX_USE_QWORD_IO 1
+#endif
+
+#ifdef EFX_USE_QWORD_IO
+static inline void _efx_writeq(struct efx_nic *efx, __le64 value,
+				  unsigned int reg)
+{
+	__raw_writeq((__force u64)value, efx->membase + reg);
+}
+static inline __le64 _efx_readq(struct efx_nic *efx, unsigned int reg)
+{
+	return (__force __le64)__raw_readq(efx->membase + reg);
+}
+#endif
+
+static inline void _efx_writed(struct efx_nic *efx, __le32 value,
+				  unsigned int reg)
+{
+	__raw_writel((__force u32)value, efx->membase + reg);
+}
+static inline __le32 _efx_readd(struct efx_nic *efx, unsigned int reg)
+{
+	return (__force __le32)__raw_readl(efx->membase + reg);
+}
+
+/* Writes to a normal 16-byte Efx register, locking as appropriate. */
+static inline void efx_writeo(struct efx_nic *efx, efx_oword_t *value,
+			      unsigned int reg)
+{
+	unsigned long flags __attribute__ ((unused));
+
+	EFX_REGDUMP(efx, "writing register %x with " EFX_OWORD_FMT "\n", reg,
+		    EFX_OWORD_VAL(*value));
+
+	spin_lock_irqsave(&efx->biu_lock, flags);
+#ifdef EFX_USE_QWORD_IO
+	_efx_writeq(efx, value->u64[0], reg + 0);
+	wmb();
+	_efx_writeq(efx, value->u64[1], reg + 8);
+#else
+	_efx_writed(efx, value->u32[0], reg + 0);
+	_efx_writed(efx, value->u32[1], reg + 4);
+	_efx_writed(efx, value->u32[2], reg + 8);
+	wmb();
+	_efx_writed(efx, value->u32[3], reg + 12);
+#endif
+	mmiowb();
+	spin_unlock_irqrestore(&efx->biu_lock, flags);
+}
+
+/* Write an 8-byte NIC SRAM entry through the supplied mapping,
+ * locking as appropriate. */
+static inline void efx_sram_writeq(struct efx_nic *efx, void __iomem *membase,
+				   efx_qword_t *value, unsigned int index)
+{
+	unsigned int addr = index * sizeof(*value);
+	unsigned long flags __attribute__ ((unused));
+
+	EFX_REGDUMP(efx, "writing SRAM address %x with " EFX_QWORD_FMT "\n",
+		    addr, EFX_QWORD_VAL(*value));
+
+	spin_lock_irqsave(&efx->biu_lock, flags);
+#ifdef EFX_USE_QWORD_IO
+	__raw_writeq((__force u64)value->u64[0], membase + addr);
+#else
+	__raw_writel((__force u32)value->u32[0], membase + addr);
+	wmb();
+	__raw_writel((__force u32)value->u32[1], membase + addr + 4);
+#endif
+	mmiowb();
+	spin_unlock_irqrestore(&efx->biu_lock, flags);
+}
+
+/* Write dword to NIC register that allows partial writes
+ *
+ * Some registers (EVQ_RPTR_REG, RX_DESC_UPD_REG and
+ * TX_DESC_UPD_REG) can be written to as a single dword.  This allows
+ * for lockless writes.
+ */
+static inline void efx_writed(struct efx_nic *efx, efx_dword_t *value,
+			      unsigned int reg)
+{
+	EFX_REGDUMP(efx, "writing partial register %x with "EFX_DWORD_FMT"\n",
+		    reg, EFX_DWORD_VAL(*value));
+
+	/* No lock required */
+	_efx_writed(efx, value->u32[0], reg);
+}
+
+/* Read from a NIC register
+ *
+ * This reads an entire 16-byte register in one go, locking as
+ * appropriate.  It is essential to read the first dword first, as this
+ * prompts the NIC to load the current value into the shadow register.
+ */
+static inline void efx_reado(struct efx_nic *efx, efx_oword_t *value,
+			     unsigned int reg)
+{
+	unsigned long flags __attribute__ ((unused));
+
+	spin_lock_irqsave(&efx->biu_lock, flags);
+	value->u32[0] = _efx_readd(efx, reg + 0);
+	rmb();
+	value->u32[1] = _efx_readd(efx, reg + 4);
+	value->u32[2] = _efx_readd(efx, reg + 8);
+	value->u32[3] = _efx_readd(efx, reg + 12);
+	spin_unlock_irqrestore(&efx->biu_lock, flags);
+
+	EFX_REGDUMP(efx, "read from register %x, got " EFX_OWORD_FMT "\n", reg,
+		    EFX_OWORD_VAL(*value));
+}
+
+/* Read an 8-byte SRAM entry through supplied mapping,
+ * locking as appropriate. */
+static inline void efx_sram_readq(struct efx_nic *efx, void __iomem *membase,
+				  efx_qword_t *value, unsigned int index)
+{
+	unsigned int addr = index * sizeof(*value);
+	unsigned long flags __attribute__ ((unused));
+
+	spin_lock_irqsave(&efx->biu_lock, flags);
+#ifdef EFX_USE_QWORD_IO
+	value->u64[0] = (__force __le64)__raw_readq(membase + addr);
+#else
+	value->u32[0] = (__force __le32)__raw_readl(membase + addr);
+	rmb();
+	value->u32[1] = (__force __le32)__raw_readl(membase + addr + 4);
+#endif
+	spin_unlock_irqrestore(&efx->biu_lock, flags);
+
+	EFX_REGDUMP(efx, "read from SRAM address %x, got "EFX_QWORD_FMT"\n",
+		    addr, EFX_QWORD_VAL(*value));
+}
+
+/* Read dword from register that allows partial writes (sic) */
+static inline void efx_readd(struct efx_nic *efx, efx_dword_t *value,
+				unsigned int reg)
+{
+	value->u32[0] = _efx_readd(efx, reg);
+	EFX_REGDUMP(efx, "read from register %x, got "EFX_DWORD_FMT"\n",
+		    reg, EFX_DWORD_VAL(*value));
+}
+
+/* Write to a register forming part of a table */
+static inline void efx_writeo_table(struct efx_nic *efx, efx_oword_t *value,
+				      unsigned int reg, unsigned int index)
+{
+	efx_writeo(efx, value, reg + index * sizeof(efx_oword_t));
+}
+
+/* Read to a register forming part of a table */
+static inline void efx_reado_table(struct efx_nic *efx, efx_oword_t *value,
+				     unsigned int reg, unsigned int index)
+{
+	efx_reado(efx, value, reg + index * sizeof(efx_oword_t));
+}
+
+/* Write to a dword register forming part of a table */
+static inline void efx_writed_table(struct efx_nic *efx, efx_dword_t *value,
+				       unsigned int reg, unsigned int index)
+{
+	efx_writed(efx, value, reg + index * sizeof(efx_oword_t));
+}
+
+/* Page-mapped register block size */
+#define EFX_PAGE_BLOCK_SIZE 0x2000
+
+/* Calculate offset to page-mapped register block */
+#define EFX_PAGED_REG(page, reg) \
+	((page) * EFX_PAGE_BLOCK_SIZE + (reg))
+
+/* As for efx_writeo(), but for a page-mapped register. */
+static inline void efx_writeo_page(struct efx_nic *efx, efx_oword_t *value,
+				   unsigned int reg, unsigned int page)
+{
+	efx_writeo(efx, value, EFX_PAGED_REG(page, reg));
+}
+
+/* As for efx_writed(), but for a page-mapped register. */
+static inline void efx_writed_page(struct efx_nic *efx, efx_dword_t *value,
+				   unsigned int reg, unsigned int page)
+{
+	efx_writed(efx, value, EFX_PAGED_REG(page, reg));
+}
+
+/* Write dword to page-mapped register with an extra lock.
+ *
+ * As for efx_writed_page(), but for a register that suffers from
+ * SFC bug 3181. Take out a lock so the BIU collector cannot be
+ * confused. */
+static inline void efx_writed_page_locked(struct efx_nic *efx,
+					  efx_dword_t *value,
+					  unsigned int reg,
+					  unsigned int page)
+{
+	unsigned long flags __attribute__ ((unused));
+
+	if (page == 0) {
+		spin_lock_irqsave(&efx->biu_lock, flags);
+		efx_writed(efx, value, EFX_PAGED_REG(page, reg));
+		spin_unlock_irqrestore(&efx->biu_lock, flags);
+	} else {
+		efx_writed(efx, value, EFX_PAGED_REG(page, reg));
+	}
+}
+
+#endif /* EFX_IO_H */